diff --git a/inc/DAVResource.php b/inc/DAVResource.php
index 5ca4f3f0..9316f361 100644
--- a/inc/DAVResource.php
+++ b/inc/DAVResource.php
@@ -1597,6 +1597,7 @@ EOQRY;
       case 'urn:ietf:params:xml:ns:carddav:address-data':
       case 'urn:ietf:params:xml:ns:caldav:calendar-data':
         if ( $this->_is_collection ) return false;
+        if ( !isset($c->sync_resource_data_ok) || $c->sync_resource_data_ok == false ) return false;
         if ( !isset($this->resource) ) $this->FetchResource();
         $reply->NSElement($prop, $tag, $this->resource->caldav_data );
         break;
diff --git a/inc/caldav-REPORT-sync-collection.php b/inc/caldav-REPORT-sync-collection.php
index 19f0820b..be6fbeb0 100644
--- a/inc/caldav-REPORT-sync-collection.php
+++ b/inc/caldav-REPORT-sync-collection.php
@@ -91,6 +91,10 @@ EOSQL;
   $first_status = 0;
   
   if ( $qry->Exec("REPORT",__LINE__,__FILE__) ) {
+    if ( $qry->rows() > 50 ) {
+      // If there are more than 50 rows to send we should not send full data in response ...
+      $c->sync_resource_data_ok = false;
+    }
     while( $object = $qry->Fetch() ) {
       if ( $object->dav_name == $last_dav_name ) {
         /** The complex case: this is the second or subsequent for this dav_id */